Are the characters alive or dead when they're cremated? Whose POV is the scene from? When in doubt, you could do something like, "One by one the six corpses were thrust into the fire, and each one's ashes cleared away to make room for the next."
Not sure I understand the question, but I'll try and roll with it anyway.
Sounds to me like it's one of those times when telling might work better than showing. You could describe the first character's cremation in great detail, craft a gut-wrenching, emotional masterpiece of a scene. Then simply tell the readers about the rest in one paragraph. One sentence, even.
If you had three or four bodies, I'd say start shifting the focus to what people say or do while each is done: words of remembering, people's reactions, which one gets someone to vow vengeance, whatever.
If you have six, I'd say have three or four-- or shift to Telling, like MFreako said.